netdev - Re: [PATCH v2 bpf-next 2/3] bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.

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Message-ID: <2f6df382-e752-2a53-0d2e-5d46c0567bff@fb.com>
Date:   Mon, 1 Nov 2021 16:11:54 -0700
From:   Yonghong Song <yhs@...com>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
CC:     "David S. Miller" <davem@...emloft.net>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Network Development <netdev@...r.kernel.org>,
        bpf <bpf@...r.kernel.org>, Kernel Team <kernel-team@...com>
Subject: Re: [PATCH v2 bpf-next 2/3] bpf: Fix propagation of signed bounds
 from 64-bit min/max into 32-bit.



On 11/1/21 4:06 PM, Alexei Starovoitov wrote:
> On Mon, Nov 1, 2021 at 4:03 PM Yonghong Song <yhs@...com> wrote:
>>
>>
>>
>> On 11/1/21 3:21 PM, Alexei Starovoitov wrote:
>>> From: Alexei Starovoitov <ast@...nel.org>
>>>
>>> Similar to unsigned bounds propagation fix signed bounds.
>>> The 'Fixes' tag is a hint. There is no security bug here.
>>> The verifier was too conservative.
>>>
>>> Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking")
>>> Signed-off-by: Alexei Starovoitov <ast@...nel.org>
>>
>> The change looks good. Should a new test_verifier test be added
>> to exercise the new change?
> 
> I think manually string comparing output the way VERBOSE_ACCEPT is doing
> is an overkill here.
> The real test case in .c will take some time to craft.

Okay. Sounds good to me.

Acked-by: Yonghong Song <yhs@...com>